Weird portability issue in TestLib.pm's slurp_file

For grins I tried running the TAP tests on my ancient HPUX box that
hosts pademelon and gaur.  At first they showed a lot of failures,
which I eventually determined were happening because slurp_file was
only retrieving part of the postmaster logfile, causing issues_sql_like
to mistakenly report a failure.  I don't know exactly why slurp_file
is misbehaving; it may well be a bug in perl 5.8.9.  But anyway,
rewriting it like this makes the problem go away:

diff --git a/src/test/perl/TestLib.pm b/src/test/perl/TestLib.pm
index da67f33c7e38929067350c7cf0da8fd8c5c1e43d..3940891e5d0533af93bacf3ff4af5a6fb5f10117 100644
*** a/src/test/perl/TestLib.pm
--- b/src/test/perl/TestLib.pm
*************** sub slurp_dir
*** 158,166 ****  sub slurp_file {     local $/;
!     local @ARGV = @_;
!     my $contents = <>;     $contents =~ s/\r//g if $Config{osname} eq 'msys';     return $contents; }
--- 158,169 ----  sub slurp_file {
+     my ($filename) = @_;     local $/;
!     open(my $in, $filename)
!       or die "could not read \"$filename\": $!";
!     my $contents = <$in>;
!     close $in;     $contents =~ s/\r//g if $Config{osname} eq 'msys';     return $contents; }

To my admittedly-no-perl-expert eye, the existing coding is too cute
by half anyway, eg what it will do in error situations is documented
nowhere that I can find in man perlop.

Any objections to pushing this?
        regards, tom lane

PS: I'm not planning to turn on TAP testing on pademelon/gaur; looks like
that would add about 40 minutes to what's already an hour and a half per
buildfarm run.  But it might be good to check it manually every so often.